Tech Update

Leveraging Additive Manufacturing for Auto Production

This aftermarket automotive LED headlight, resulting from optimized AM, illustrates how AM can succeed in higher-volume automotive applications.

High volumes, productivity and cost-per-part often are cited as reasons why additive manufacturing (AM), especially with metal materials, is not conducive to automotive-industry production applications. Challenging the status quo, one company reports working on a specific automotive project using the laser powder-bed-fusion (LPBF) process to produce 384 qualified metal parts in a single build. This was achieved through design expertise and unique optimization technology that translated to reduced part costs—$4 versus $40-plus—and reduced lead times—from 444 to 34 hr.

The key to making AM productive enough for wider adoption across high-volume industries such as automotive, however, lies in process economics. That is, choosing the most effective manufacturing process for each part. Combining these principles with knowledge of the limits of additive—as well as how and when to push them—together with its optimization technology, enables UK-based Betatype to provide design and production of parts that are economically viable against existing mass-production technologies.

Fighting Against Conventional Wisdom

Often AM is described as a process that is capable of any geometry. In reality, AM can provide greater design freedom than other traditional manufacturing processes, but still comes with its own set of constraints. Understanding these constraints is imperative to identifying applications that fit well with AM, namely those with specifically complex geometries that work best with the physics of additive processes. This thinking has traditionally only been applied to low-volume parts, however.

Die casting and other traditional manufacturing processes can produce millions of components per year, while AM processes such as LPBF can excel and add value by delivering geometric complexity with the least amount of material possible, but not economically at high volumes. This has long been a trade-off, one that has seen automotive companies dismiss AM for production applications—but such thinking is changing.

Case Study: Automotive LED Headlights

A stacked build of automotive LED-headlight heatsinks. Designing the part with in-built support features allowed multiple parts to be stacked on top of each other without the need for additional supports. As a result, finished parts could be snapped apart by hand, without the need for further post-processing.

The right part can help industry break conventional thinking about LPBF. A demonstration can be found in the automotive industry’s switch to the use of LED headlights. Typically, these components require comparatively large, often actively cooled heatsinks. Betatype, which works with customers to deliver functional components through AM, and built Engine, a data-processing platform for managing and controlling multi-scale design, saw an opportunity. The company recognized that the specific geometry for these metal parts made them ideal for producing via LPBF, which can consolidate multiple manufacturing processes into a single production method.

By considering the LPBF process during the component’s initial design stage, Betatype was able to design a part with in-built support features, allowing multiple headlight parts to be stacked on top of each other without the need for additional supports. As a result, finished parts could be snapped apart by hand, without the need for further post-processing.

Full stacking, often deemed difficult with LPBF due to thermal stresses involved in the layer process, was achieved through intelligent design of the structure. This reduced thermal stresses, leading to minimal thermal distortion. Innovative part design enabled a series of parts to be nested to maximize build volume, resulting in 384 parts produced within a single build envelope. UK-based Progressive Technology built the parts using an EOS 280M system.

Reduced Build Times and Costs

Betatype’s design and data-processing technology enabled every toolpath within each part to be designed, managed and optimized. Through specific control parameters, exposure of the part in each layer to a single laser-melting toolpath was reduced significantly, with minimal delays in between. This, coupled with the company’s optimization algorithms and process technology, reduced build time of each part from 1 hr. to less than 5 min.–reportedly 10 times faster than using a standard build processor.

Reducing build times is key to making parts more cost-effective with LPBF, as equipment amortization represents a major part-cost driver. Betatype’s optimization technology played a significant role here in decreasing cost/part from $40-plus to less than $4.

Moreover, on single-laser, medium-frame printing systems, this technology helped reduce build time from 444 hr. to less than 30 hr. for the 384 parts. With new multi-laser, medium-frame systems this optimization approach reduced build time to less than 19 hr. Using these high-productivity systems, it was possible to realize a 19-fold gain in productivity across a year of production per system, from 7055 to 135,168 parts. Installation of seven machines running the optimized process results in volumes approaching 1 million parts/yr. 3DMP